Pension Accounting Demystified: Understanding Net Periodic Pension Cost

Why Pension Accounting Is So Confusing

Pension accounting is the topic students find most intimidating. But once you understand what a defined benefit pension plan is and what the accounting is trying to capture, the components become much easier to learn.

Defined Benefit vs Defined Contribution

In a defined contribution plan, the employer makes contributions and the employee bears the investment risk. The accounting is simple: expense equals the contribution. In a defined benefit plan, the employer promises a specific retirement benefit and bears all the investment risk — hence the complex accounting.

The Six Components of Net Periodic Pension Cost

Service cost — the present value of benefits earned this year, always increases expense. Interest cost — the cost of carrying the projected benefit obligation for another year. Expected return on plan assets — reduces pension expense. Amortisation of prior service cost — from plan amendments, recognised first in OCI then amortised into expense. Amortisation of actuarial gains and losses — using the 10% corridor method. Amortisation of net transition obligation — largely worked through the system for most employers.

The Balance Sheet: Funded Status

The balance sheet presents funded status — fair value of plan assets minus the projected benefit obligation. If plan assets exceed the PBO, the plan is overfunded (net pension asset). If the PBO exceeds plan assets, it is underfunded (net pension liability). The difference between funded status and cumulative pension expense flows through other comprehensive income.